Before he was the notorious Blind Sheikh, the spiritual advisor and instigator of the 1993 World Trade Center bombers, and a convicted terrorist in his own right, Omar Abdel Rahman was a guest of the American government. Between 1986 and 1989, the Egyptian-born Rahman applied at least four times for a U.S. tourist visa (such visas typically last 90 days). Already a credentialed militant, he had in 1987 earned a place on the State Department’s terrorist watch list for his fatwa, years earlier, urging the assassination of Egyptian president Anwar Sadat and for his relentless preaching of jihadist violence. But only once did the U.S. refuse him a visa. By then, it was too late.

Andrew McCarthy was the lead federal prosecutor of the World Trade Center bombing conspiracy trial in 1995 and the man who would put Rahman away for life. When he invokes “willful blindness” in the title of his absorbing new book, it is this depressing history—a fatal mixture of bureaucratic bungling and strategic shortsightedness—that he has in mind. Part survey of Islamic terror in the 1980s and nineties, part memoir of the nine-month trial that brought the World Trade Center bombers to justice, Willful Blindness is a bracing chronicle of the first major terrorist attack on American soil and a valuable reminder that radical Islam was a real and present threat to the United States long before September 11.

It would be difficult to document every government failure in the run-up to the 1993 bombings, but McCarthy’s meticulous account surely comes close. Consider the case of Mahmud Abouhalima. Later to become the plot’s de facto leader, he received a residency visa as an “agricultural worker” under the 1986 immigration bill—this despite the fact that he was employed as a cab driver. Perhaps, as McCarthy aridly notes, he was “tending to the fecund fields of Brooklyn.” But oversights like these are mere peccadilloes next to the FBI’s craven 1989 decision to stop monitoring the men who would become the World Trade Center bombers. No sooner did the terrorist trainees charge that their surveillance by FBI agents—at a firing range in Long Island, no less—constituted religious harassment than the agency hurriedly closed the book on the investigation. Nothing to see here, folks: just a few pious citizens taking their AK-47s out for target practice.

Still, at least there was an investigation. Not so in November 1990, when an Egyptian radical named Sayyid Nosair, his skills honed at the shooting range, gunned down Jewish Defense League leader Rabbi Meir Kahane. Had the FBI pursued leads in the assassination, it would have discovered Nosair’s involvement in the conspiracy to attack the World Trade Center and other American locations as well. Instead, the agency deferred to the unsound judgment of the New York Police Department, which pronounced Kahane’s murder the work of a lone gunman. The bombing plot went forth as planned.

Most damning, perhaps, is the studious inattention that the Bureau and the entire national security bureaucracy paid to the Blind Sheikh. For years before the 1993 bombing, Rahman played a double game, disavowing terrorist strikes in public while winkingly blessing attacks by his zealous followers. Cleverness finally caught up with him when an FBI informant, an erratic Egyptian named Emad Salem, recorded the sheikh as he approved terrorist attacks against the United Nations and urged strikes against the U.S. Army. These directives would prove critical to McCarthy’s successful case against Rahman.

Lest one give the FBI too much credit even here, McCarthy points out that Salem’s breakthrough nearly didn’t happen. Fearing the fallout if a bombing were to occur on its watch, the FBI at one point instructed Salem that he could talk about bombs but not assist the conspiracy by touching actual bomb parts. A shrewd caveat, one might think—except that Salem’s cover as a bomb expert would have been blown had he followed the directive. In any case, before that could happen, a feud between the informant and his FBI handlers drove Salem away just before the bombing, though he reemerged in the aftermath to help prosecute the plotters.

McCarthy does not exempt himself from harsh criticism. Like so many government officials in the years before Osama bin Laden became a household name, McCarthy admits, he began with a serious blind spot about Islam. Initially believing that preachers like Rahman could be discredited as “fundamentalist crazies,” he came to realize with dismay that their justifications for terrorism were taken directly from foundational Islamic texts. On the legal front, McCarthy blames himself for allowing the bombing conspirator Ahmed Abdel Sattar to escape prosecution. Deeming the evidence too weak for a conviction—a conclusion he now regrets—McCarthy declined to prosecute Sattar. Savoring his reprieve, Sattar spent the next ten years helping the imprisoned Rahman direct his terrorist followers in Egypt. He was not apprehended until 2005.

For McCarthy, the institutional failures of the 1990s were not accidental. Rather, they were the inevitable consequences of treating terrorism as a criminal matter. Indeed, central to McCarthy’s narrative is his view that the U.S. criminal justice system, for all its virtues, was woefully unprepared to defend the country against Islamic terrorism. At the time of the 1993 bombing, for instance, there was no special provision in the law covering bombing conspiracy—meaning that at most the terrorists could get five years under a federal conspiracy statute. Prosecutors also had to prove that a “substantial step” had been taken to commit a crime—a measure that created a perverse incentive to let terrorist conspiracies proceed until the last possible second.

During the trial, too, there was no shortage of trouble. In complying with discovery rules, McCarthy had to turn over his list of hundreds of unindicted co-conspirators to the individuals named therein. These included one Ali Mohamed, whom McCarthy suspected of being a terrorist. Presciently, as it turned out: upon receiving the list, which included Osama bin Laden’s name, Mohammed relayed it to al-Qaida operatives, giving them a valuable glimpse into the state of U.S. intelligence. Civil liberties absolutists who demand due-process rights for terrorist captives, ignoring the consequences for national security, would do well to study McCarthy’s chapters on the trial.

Compelling as his book is, one wishes that McCarthy had advanced some alternatives to the flawed criminal-justice strategy he so powerfully exposes. Legal scholars like Jack Goldsmith, for example, have urged the creation of national security courts as an alternative to the traditional variety. Administered by independent rather than military judges, but governed by rules of evidence that would not compromise national security, these courts could conceivably satisfy both sides of the national-security debate. McCarthy’s background would make his view of such proposals worth hearing.

Such omissions are the exception, however, in this impressively detailed book. Willful Blindness sometimes makes for painful reading, returning as it does to a time when, to adapt Trostky’s line, the U.S. was not interested in Islamic jihad but Islamic jihad was very much interested in the U.S. But then, it is precisely because the temptation to do nothing is ever-present that, 15 years after the World Trade Center bombing, McCarthy’s chronicle of opportunities missed reads like such a contemporary tale.